*
* Bacon's thin locks have a fast path that doesn't need a lock record
* for the common case of locking an unlocked or shallow-nested
- * object, but the technique relies on encoding the thread ID in 15
- * bits (to avoid too much per-object space overhead.) Unfortunately
- * I don't think it's possible to reliably encode a pthread_t into 15
- * bits. (The JVM implementation used seems to have a 15-bit
- * per-thread identifier available.)
- *
- * This implementation then combines Dice's basic lock model with
- * Bacon's simplification of keeping a lock record for the lifetime of
- * an object.
+ * object.
*/
static MonitorArray *monitor_allocated;
static int array_size = 16;
+/* MonoThreadsSync status helpers */
+
static inline guint32
mon_status_get_owner (guint32 status)
{
return status & ENTRY_COUNT_WAITERS;
}
+/* LockWord helpers */
+
+static inline MonoThreadsSync*
+lock_word_get_inflated_lock (LockWord lw)
+{
+ lw.lock_word &= (~LOCK_WORD_STATUS_MASK);
+ return lw.sync;
+}
+
+static inline gboolean
+lock_word_is_inflated (LockWord lw)
+{
+ return lw.lock_word & LOCK_WORD_INFLATED;
+}
+
+static inline gboolean
+lock_word_has_hash (LockWord lw)
+{
+ return lw.lock_word & LOCK_WORD_HAS_HASH;
+}
+
+static inline LockWord
+lock_word_set_has_hash (LockWord lw)
+{
+ LockWord nlw;
+ nlw.lock_word = lw.lock_word | LOCK_WORD_HAS_HASH;
+ return nlw;
+}
+
+static inline gboolean
+lock_word_is_free (LockWord lw)
+{
+ return !lw.lock_word;
+}
+
+static inline gboolean
+lock_word_is_flat (LockWord lw)
+{
+ /* Return whether the lock is flat or free */
+ return (lw.lock_word & LOCK_WORD_STATUS_MASK) == LOCK_WORD_FLAT;
+}
+
+static inline gint32
+lock_word_get_hash (LockWord lw)
+{
+ return (gint32) (lw.lock_word >> LOCK_WORD_HASH_SHIFT);
+}
+
+static inline gint32
+lock_word_get_nest (LockWord lw)
+{
+ if (lock_word_is_free (lw))
+ return 0;
+ /* Inword nest count starts from 0 */
+ return ((lw.lock_word & LOCK_WORD_NEST_MASK) >> LOCK_WORD_NEST_SHIFT) + 1;
+}
+
+static inline gboolean
+lock_word_is_nested (LockWord lw)
+{
+ return lw.lock_word & LOCK_WORD_NEST_MASK;
+}
+
+static inline gboolean
+lock_word_is_max_nest (LockWord lw)
+{
+ return (lw.lock_word & LOCK_WORD_NEST_MASK) == LOCK_WORD_NEST_MASK;
+}
+
+static inline LockWord
+lock_word_increment_nest (LockWord lw)
+{
+ lw.lock_word += 1 << LOCK_WORD_NEST_SHIFT;
+ return lw;
+}
+
+static inline LockWord
+lock_word_decrement_nest (LockWord lw)
+{
+ lw.lock_word -= 1 << LOCK_WORD_NEST_SHIFT;
+ return lw;
+}
+
+static inline gint32
+lock_word_get_owner (LockWord lw)
+{
+ return lw.lock_word >> LOCK_WORD_OWNER_SHIFT;
+}
+
+static inline LockWord
+lock_word_new_thin_hash (gint32 hash)
+{
+ LockWord lw;
+ lw.lock_word = (guint32)hash;
+ lw.lock_word = (lw.lock_word << LOCK_WORD_HASH_SHIFT) | LOCK_WORD_HAS_HASH;
+ return lw;
+}
+
+static inline LockWord
+lock_word_new_inflated (MonoThreadsSync *mon)
+{
+ LockWord lw;
+ lw.sync = mon;
+ lw.lock_word |= LOCK_WORD_INFLATED;
+ return lw;
+}
+
+static inline LockWord
+lock_word_new_flat (gint32 owner)
+{
+ LockWord lw;
+ lw.lock_word = owner;
+ lw.lock_word <<= LOCK_WORD_OWNER_SHIFT;
+ return lw;
+}
+
void
mono_monitor_init (void)
{
for (mon = monitor_freelist; mon; mon = mon->data)
mon->wait_list = (gpointer)-1;
- /* FIXME: This still crashes with sgen (async_read.exe) */
+ /*
+ * FIXME: This still crashes with sgen (async_read.exe)
+ *
+ * In mini_cleanup() we first call mono_runtime_cleanup(), which calls
+ * mono_monitor_cleanup(), which is supposed to free all monitor memory.
+ *
+ * Later in mini_cleanup(), we call mono_domain_free(), which calls
+ * mono_gc_clear_domain(), which frees all weak links associated with objects.
+ * Those weak links reside in the monitor structures, which we've freed earlier.
+ *
+ * Unless we fix this dependency in the shutdown sequence this code has to remain
+ * disabled, or at least the call to g_free().
+ */
/*
for (marray = monitor_allocated; marray; marray = next) {
int i;
to_recycle++;
} else {
if (!monitor_is_on_freelist (mon->data)) {
- MonoObject *holder = mono_gc_weak_link_get (&mon->data);
+ MonoObject *holder = (MonoObject *)mono_gchandle_get_target ((guint32)mon->data);
if (mon_status_get_owner (mon->status)) {
g_print ("Lock %p in object %p held by thread %d, nest level: %d\n",
mon, holder, mon_status_get_owner (mon->status), mon->nest);
new = NULL;
for (marray = monitor_allocated; marray; marray = marray->next) {
for (i = 0; i < marray->num_monitors; ++i) {
- if (marray->monitors [i].data == NULL) {
+ if (mono_gchandle_get_target ((guint32)marray->monitors [i].data) == NULL) {
new = &marray->monitors [i];
if (new->wait_list) {
/* Orphaned events left by aborted threads */
new->wait_list = g_slist_remove (new->wait_list, new->wait_list->data);
}
}
- mono_gc_weak_link_remove (&new->data, TRUE);
+ mono_gchandle_free ((guint32)new->data);
new->data = monitor_freelist;
monitor_freelist = new;
}
return new;
}
-/*
- * Format of the lock word:
- * thinhash | fathash | data
- *
- * thinhash is the lower bit: if set data is the shifted hashcode of the object.
- * fathash is another bit: if set the hash code is stored in the MonoThreadsSync
- * struct pointed to by data
- * if neither bit is set and data is non-NULL, data is a MonoThreadsSync
- */
-typedef union {
- gsize lock_word;
- MonoThreadsSync *sync;
-} LockWord;
+static MonoThreadsSync*
+alloc_mon (MonoObject *obj, gint32 id)
+{
+ MonoThreadsSync *mon;
-enum {
- LOCK_WORD_THIN_HASH = 1,
- LOCK_WORD_FAT_HASH = 1 << 1,
- LOCK_WORD_BITS_MASK = 0x3,
- LOCK_WORD_HASH_SHIFT = 2
-};
+ mono_monitor_allocator_lock ();
+ mon = mon_new (id);
+ mon->data = (void *)(size_t)mono_gchandle_new_weakref (obj, TRUE);
+ mono_monitor_allocator_unlock ();
+
+ return mon;
+}
+
+
+static void
+discard_mon (MonoThreadsSync *mon)
+{
+ mono_monitor_allocator_lock ();
+ mono_gchandle_free ((guint32)mon->data);
+ mon_finalize (mon);
+ mono_monitor_allocator_unlock ();
+}
+
+static void
+mono_monitor_inflate_owned (MonoObject *obj, int id)
+{
+ MonoThreadsSync *mon;
+ LockWord nlw, old_lw, tmp_lw;
+ guint32 nest;
+
+ old_lw.sync = obj->synchronisation;
+ LOCK_DEBUG (g_message ("%s: (%d) Inflating owned lock object %p; LW = %p", __func__, id, obj, old_lw.sync));
+
+ if (lock_word_is_inflated (old_lw)) {
+ /* Someone else inflated the lock in the meantime */
+ return;
+ }
+
+ mon = alloc_mon (obj, id);
+
+ nest = lock_word_get_nest (old_lw);
+ mon->nest = nest;
+
+ nlw = lock_word_new_inflated (mon);
+
+ mono_memory_write_barrier ();
+ tmp_lw.sync = InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, nlw.sync, old_lw.sync);
+ if (tmp_lw.sync != old_lw.sync) {
+ /* Someone else inflated the lock in the meantime */
+ discard_mon (mon);
+ }
+}
+
+static void
+mono_monitor_inflate (MonoObject *obj)
+{
+ MonoThreadsSync *mon;
+ LockWord nlw, old_lw;
+
+ LOCK_DEBUG (g_message ("%s: (%d) Inflating lock object %p; LW = %p", __func__, mono_thread_info_get_small_id (), obj, obj->synchronisation));
+
+ mon = alloc_mon (obj, 0);
+
+ nlw = lock_word_new_inflated (mon);
+
+ old_lw.sync = obj->synchronisation;
+
+ for (;;) {
+ LockWord tmp_lw;
+
+ if (lock_word_is_inflated (old_lw)) {
+ break;
+ }
+#ifdef HAVE_MOVING_COLLECTOR
+ else if (lock_word_has_hash (old_lw)) {
+ mon->hash_code = lock_word_get_hash (old_lw);
+ mon->status = mon_status_set_owner (mon->status, 0);
+ nlw = lock_word_set_has_hash (nlw);
+ }
+#endif
+ else if (lock_word_is_free (old_lw)) {
+ mon->status = mon_status_set_owner (mon->status, 0);
+ mon->nest = 1;
+ } else {
+ /* Lock is flat */
+ mon->status = mon_status_set_owner (mon->status, lock_word_get_owner (old_lw));
+ mon->nest = lock_word_get_nest (old_lw);
+ }
+ mono_memory_write_barrier ();
+ tmp_lw.sync = InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, nlw.sync, old_lw.sync);
+ if (tmp_lw.sync == old_lw.sync) {
+ /* Successfully inflated the lock */
+ return;
+ }
+
+ old_lw.sync = tmp_lw.sync;
+ }
+
+ /* Someone else inflated the lock before us */
+ discard_mon (mon);
+}
#define MONO_OBJECT_ALIGNMENT_SHIFT 3
if (!obj)
return 0;
lw.sync = obj->synchronisation;
- if (lw.lock_word & LOCK_WORD_THIN_HASH) {
- /*g_print ("fast thin hash %d for obj %p store\n", (unsigned int)lw.lock_word >> LOCK_WORD_HASH_SHIFT, obj);*/
- return (unsigned int)lw.lock_word >> LOCK_WORD_HASH_SHIFT;
- }
- if (lw.lock_word & LOCK_WORD_FAT_HASH) {
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- /*g_print ("fast fat hash %d for obj %p store\n", lw.sync->hash_code, obj);*/
- return lw.sync->hash_code;
+
+ LOCK_DEBUG (g_message("%s: (%d) Get hash for object %p; LW = %p", __func__, mono_thread_info_get_small_id (), obj, obj->synchronisation));
+
+ if (lock_word_has_hash (lw)) {
+ if (lock_word_is_inflated (lw)) {
+ return lock_word_get_inflated_lock (lw)->hash_code;
+ } else {
+ return lock_word_get_hash (lw);
+ }
}
/*
* while we are inside this function, the GC will keep this object pinned,
* with the same value.
*/
hash = (GPOINTER_TO_UINT (obj) >> MONO_OBJECT_ALIGNMENT_SHIFT) * 2654435761u;
+#if SIZEOF_VOID_P == 4
/* clear the top bits as they can be discarded */
- hash &= ~(LOCK_WORD_BITS_MASK << 30);
- /* no hash flags were set, so it must be a MonoThreadsSync pointer if not NULL */
- if (lw.sync) {
- lw.sync->hash_code = hash;
- /*g_print ("storing hash code %d for obj %p in sync %p\n", hash, obj, lw.sync);*/
- lw.lock_word |= LOCK_WORD_FAT_HASH;
- /* this is safe since we don't deflate locks */
- obj->synchronisation = lw.sync;
- } else {
- /*g_print ("storing thin hash code %d for obj %p\n", hash, obj);*/
- lw.lock_word = LOCK_WORD_THIN_HASH | (hash << LOCK_WORD_HASH_SHIFT);
- if (InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, lw.sync, NULL) == NULL)
+ hash &= ~(LOCK_WORD_STATUS_MASK << (32 - LOCK_WORD_STATUS_BITS));
+#endif
+ if (lock_word_is_free (lw)) {
+ LockWord old_lw;
+ lw = lock_word_new_thin_hash (hash);
+
+ old_lw.sync = InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, lw.sync, NULL);
+ if (old_lw.sync == NULL) {
return hash;
- /*g_print ("failed store\n");*/
- /* someone set the hash flag or someone inflated the object */
- lw.sync = obj->synchronisation;
- if (lw.lock_word & LOCK_WORD_THIN_HASH)
+ }
+
+ if (lock_word_has_hash (old_lw)) {
+ /* Done by somebody else */
return hash;
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- lw.sync->hash_code = hash;
- lw.lock_word |= LOCK_WORD_FAT_HASH;
- /* this is safe since we don't deflate locks */
- obj->synchronisation = lw.sync;
+ }
+
+ mono_monitor_inflate (obj);
+ lw.sync = obj->synchronisation;
+ } else if (lock_word_is_flat (lw)) {
+ int id = mono_thread_info_get_small_id ();
+ if (lock_word_get_owner (lw) == id)
+ mono_monitor_inflate_owned (obj, id);
+ else
+ mono_monitor_inflate (obj);
+ lw.sync = obj->synchronisation;
}
+
+ /* At this point, the lock is inflated */
+ lock_word_get_inflated_lock (lw)->hash_code = hash;
+ lw = lock_word_set_has_hash (lw);
+ mono_memory_write_barrier ();
+ obj->synchronisation = lw.sync;
return hash;
#else
/*
#endif
}
+static void
+mono_monitor_ensure_owned (LockWord lw, guint32 id)
+{
+ if (lock_word_is_flat (lw)) {
+ if (lock_word_get_owner (lw) == id)
+ return;
+ } else if (lock_word_is_inflated (lw)) {
+ if (mon_status_get_owner (lock_word_get_inflated_lock (lw)->status) == id)
+ return;
+ }
+
+ mono_set_pending_exception (mono_get_exception_synchronization_lock ("Object synchronization method was called from an unsynchronized block of code."));
+}
+
+/*
+ * When this function is called it has already been established that the
+ * current thread owns the monitor.
+ */
+static void
+mono_monitor_exit_inflated (MonoObject *obj)
+{
+ LockWord lw;
+ MonoThreadsSync *mon;
+ guint32 nest;
+
+ lw.sync = obj->synchronisation;
+ mon = lock_word_get_inflated_lock (lw);
+
+ nest = mon->nest - 1;
+ if (nest == 0) {
+ guint32 new_status, old_status, tmp_status;
+
+ old_status = mon->status;
+
+ /*
+ * Release lock and do the wakeup stuff. It's possible that
+ * the last blocking thread gave up waiting just before we
+ * release the semaphore resulting in a negative entry count
+ * and a futile wakeup next time there's contention for this
+ * object.
+ */
+ for (;;) {
+ gboolean have_waiters = mon_status_have_waiters (old_status);
+
+ new_status = mon_status_set_owner (old_status, 0);
+ if (have_waiters)
+ new_status = mon_status_decrement_entry_count (new_status);
+ tmp_status = InterlockedCompareExchange ((gint32*)&mon->status, new_status, old_status);
+ if (tmp_status == old_status) {
+ if (have_waiters)
+ ReleaseSemaphore (mon->entry_sem, 1, NULL);
+ break;
+ }
+ old_status = tmp_status;
+ }
+ LOCK_DEBUG (g_message ("%s: (%d) Object %p is now unlocked", __func__, mono_thread_info_get_small_id (), obj));
+
+ /* object is now unlocked, leave nest==1 so we don't
+ * need to set it when the lock is reacquired
+ */
+ } else {
+ LOCK_DEBUG (g_message ("%s: (%d) Object %p is now locked %d times", __func__, mono_thread_info_get_small_id (), obj, nest));
+ mon->nest = nest;
+ }
+}
+
+/*
+ * When this function is called it has already been established that the
+ * current thread owns the monitor.
+ */
+static void
+mono_monitor_exit_flat (MonoObject *obj, LockWord old_lw)
+{
+ LockWord new_lw, tmp_lw;
+ if (G_UNLIKELY (lock_word_is_nested (old_lw)))
+ new_lw = lock_word_decrement_nest (old_lw);
+ else
+ new_lw.lock_word = 0;
+
+ tmp_lw.sync = InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, new_lw.sync, old_lw.sync);
+ if (old_lw.sync != tmp_lw.sync) {
+ /* Someone inflated the lock in the meantime */
+ mono_monitor_exit_inflated (obj);
+ }
+
+ LOCK_DEBUG (g_message ("%s: (%d) Object %p is now locked %d times; LW = %p", __func__, mono_thread_info_get_small_id (), obj, lock_word_get_nest (new_lw), obj->synchronisation));
+}
+
static void
mon_decrement_entry_count (MonoThreadsSync *mon)
{
* is requested. In this case it returns -1.
*/
static inline gint32
-mono_monitor_try_enter_internal (MonoObject *obj, guint32 ms, gboolean allow_interruption)
+mono_monitor_try_enter_inflated (MonoObject *obj, guint32 ms, gboolean allow_interruption, guint32 id)
{
+ LockWord lw;
MonoThreadsSync *mon;
- gsize id = mono_thread_info_get_small_id ();
HANDLE sem;
guint32 then = 0, now, delta;
guint32 waitms;
LOCK_DEBUG (g_message("%s: (%d) Trying to lock object %p (%d ms)", __func__, id, obj, ms));
if (G_UNLIKELY (!obj)) {
- mono_raise_exception (mono_get_exception_argument_null ("obj"));
+ mono_set_pending_exception (mono_get_exception_argument_null ("obj"));
return FALSE;
}
+ lw.sync = obj->synchronisation;
+ mon = lock_word_get_inflated_lock (lw);
retry:
- mon = obj->synchronisation;
-
- /* If the object has never been locked... */
- if (G_UNLIKELY (mon == NULL)) {
- mono_monitor_allocator_lock ();
- mon = mon_new (id);
- if (InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, mon, NULL) == NULL) {
- mono_gc_weak_link_add (&mon->data, obj, TRUE);
- mono_monitor_allocator_unlock ();
- /* Successfully locked */
- return 1;
- } else {
-#ifdef HAVE_MOVING_COLLECTOR
- LockWord lw;
- lw.sync = obj->synchronisation;
- if (lw.lock_word & LOCK_WORD_THIN_HASH) {
- MonoThreadsSync *oldlw = lw.sync;
- /* move the already calculated hash */
- mon->hash_code = lw.lock_word >> LOCK_WORD_HASH_SHIFT;
- lw.sync = mon;
- lw.lock_word |= LOCK_WORD_FAT_HASH;
- if (InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, lw.sync, oldlw) == oldlw) {
- mono_gc_weak_link_add (&mon->data, obj, TRUE);
- mono_monitor_allocator_unlock ();
- /* Successfully locked */
- return 1;
- } else {
- mon_finalize (mon);
- mono_monitor_allocator_unlock ();
- goto retry;
- }
- } else if (lw.lock_word & LOCK_WORD_FAT_HASH) {
- mon_finalize (mon);
- mono_monitor_allocator_unlock ();
- /* get the old lock without the fat hash bit */
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- mon = lw.sync;
- } else {
- mon_finalize (mon);
- mono_monitor_allocator_unlock ();
- mon = obj->synchronisation;
- }
-#else
- mon_finalize (mon);
- mono_monitor_allocator_unlock ();
- mon = obj->synchronisation;
-#endif
- }
- } else {
-#ifdef HAVE_MOVING_COLLECTOR
- LockWord lw;
- lw.sync = mon;
- if (lw.lock_word & LOCK_WORD_THIN_HASH) {
- MonoThreadsSync *oldlw = lw.sync;
- mono_monitor_allocator_lock ();
- mon = mon_new (id);
- /* move the already calculated hash */
- mon->hash_code = lw.lock_word >> LOCK_WORD_HASH_SHIFT;
- lw.sync = mon;
- lw.lock_word |= LOCK_WORD_FAT_HASH;
- if (InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, lw.sync, oldlw) == oldlw) {
- mono_gc_weak_link_add (&mon->data, obj, TRUE);
- mono_monitor_allocator_unlock ();
- /* Successfully locked */
- return 1;
- } else {
- mon_finalize (mon);
- mono_monitor_allocator_unlock ();
- goto retry;
- }
- }
-#endif
- }
-
-#ifdef HAVE_MOVING_COLLECTOR
- {
- LockWord lw;
- lw.sync = mon;
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- mon = lw.sync;
- }
-#endif
-
- /* If the object has previously been locked but isn't now... */
-
/* This case differs from Dice's case 3 because we don't
* deflate locks or cache unused lock records
*/
* We pass TRUE instead of allow_interruption since we have to check for the
* StopRequested case below.
*/
+ MONO_PREPARE_BLOCKING;
ret = WaitForSingleObjectEx (mon->entry_sem, waitms, TRUE);
+ MONO_FINISH_BLOCKING;
mono_thread_clr_state (thread, ThreadState_WaitSleepJoin);
}
}
+/*
+ * If allow_interruption == TRUE, the method will be interrupted if abort or suspend
+ * is requested. In this case it returns -1.
+ */
+static inline gint32
+mono_monitor_try_enter_internal (MonoObject *obj, guint32 ms, gboolean allow_interruption)
+{
+ LockWord lw;
+ int id = mono_thread_info_get_small_id ();
+
+ LOCK_DEBUG (g_message("%s: (%d) Trying to lock object %p (%d ms)", __func__, id, obj, ms));
+
+ if (G_UNLIKELY (!obj)) {
+ mono_set_pending_exception (mono_get_exception_argument_null ("obj"));
+ return FALSE;
+ }
+
+ lw.sync = obj->synchronisation;
+
+ if (G_LIKELY (lock_word_is_free (lw))) {
+ LockWord nlw = lock_word_new_flat (id);
+ if (InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, nlw.sync, NULL) == NULL) {
+ return 1;
+ } else {
+ /* Someone acquired it in the meantime or put a hash */
+ mono_monitor_inflate (obj);
+ return mono_monitor_try_enter_inflated (obj, ms, allow_interruption, id);
+ }
+ } else if (lock_word_is_inflated (lw)) {
+ return mono_monitor_try_enter_inflated (obj, ms, allow_interruption, id);
+ } else if (lock_word_is_flat (lw)) {
+ if (lock_word_get_owner (lw) == id) {
+ if (lock_word_is_max_nest (lw)) {
+ mono_monitor_inflate_owned (obj, id);
+ return mono_monitor_try_enter_inflated (obj, ms, allow_interruption, id);
+ } else {
+ LockWord nlw, old_lw;
+ nlw = lock_word_increment_nest (lw);
+ old_lw.sync = InterlockedCompareExchangePointer ((gpointer*)&obj->synchronisation, nlw.sync, lw.sync);
+ if (old_lw.sync != lw.sync) {
+ /* Someone else inflated it in the meantime */
+ g_assert (lock_word_is_inflated (old_lw));
+ return mono_monitor_try_enter_inflated (obj, ms, allow_interruption, id);
+ }
+ return 1;
+ }
+ } else {
+ mono_monitor_inflate (obj);
+ return mono_monitor_try_enter_inflated (obj, ms, allow_interruption, id);
+ }
+ } else if (lock_word_has_hash (lw)) {
+ mono_monitor_inflate (obj);
+ return mono_monitor_try_enter_inflated (obj, ms, allow_interruption, id);
+ }
+
+ g_assert_not_reached ();
+ return -1;
+}
+
gboolean
mono_monitor_enter (MonoObject *obj)
{
void
mono_monitor_exit (MonoObject *obj)
{
- MonoThreadsSync *mon;
- guint32 nest;
- guint32 new_status, old_status, tmp_status;
+ LockWord lw;
LOCK_DEBUG (g_message ("%s: (%d) Unlocking %p", __func__, mono_thread_info_get_small_id (), obj));
if (G_UNLIKELY (!obj)) {
- mono_raise_exception (mono_get_exception_argument_null ("obj"));
+ mono_set_pending_exception (mono_get_exception_argument_null ("obj"));
return;
}
- mon = obj->synchronisation;
+ lw.sync = obj->synchronisation;
-#ifdef HAVE_MOVING_COLLECTOR
- {
- LockWord lw;
- lw.sync = mon;
- if (lw.lock_word & LOCK_WORD_THIN_HASH)
- return;
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- mon = lw.sync;
- }
-#endif
- if (G_UNLIKELY (mon == NULL)) {
- /* No one ever used Enter. Just ignore the Exit request as MS does */
- return;
- }
+ mono_monitor_ensure_owned (lw, mono_thread_info_get_small_id ());
- old_status = mon->status;
- if (G_UNLIKELY (mon_status_get_owner (old_status) != mono_thread_info_get_small_id ())) {
- return;
- }
-
- nest = mon->nest - 1;
- if (nest == 0) {
- /*
- * Release lock and do the wakeup stuff. It's possible that
- * the last blocking thread gave up waiting just before we
- * release the semaphore resulting in a negative entry count
- * and a futile wakeup next time there's contention for this
- * object.
- */
- for (;;) {
- gboolean have_waiters = mon_status_have_waiters (old_status);
-
- new_status = mon_status_set_owner (old_status, 0);
- if (have_waiters)
- new_status = mon_status_decrement_entry_count (new_status);
- tmp_status = InterlockedCompareExchange ((gint32*)&mon->status, new_status, old_status);
- if (tmp_status == old_status) {
- if (have_waiters)
- ReleaseSemaphore (mon->entry_sem, 1, NULL);
- break;
- }
- old_status = tmp_status;
- }
- LOCK_DEBUG (g_message ("%s: (%d) Object %p is now unlocked", __func__, mono_thread_info_get_small_id (), obj));
-
- /* object is now unlocked, leave nest==1 so we don't
- * need to set it when the lock is reacquired
- */
-
- } else {
- LOCK_DEBUG (g_message ("%s: (%d) Object %p is now locked %d times", __func__, mono_thread_info_get_small_id (), obj, nest));
- mon->nest = nest;
- }
+ if (G_UNLIKELY (lock_word_is_inflated (lw)))
+ mono_monitor_exit_inflated (obj);
+ else
+ mono_monitor_exit_flat (obj, lw);
}
-void**
-mono_monitor_get_object_monitor_weak_link (MonoObject *object)
+guint32
+mono_monitor_get_object_monitor_gchandle (MonoObject *object)
{
LockWord lw;
- MonoThreadsSync *sync = NULL;
lw.sync = object->synchronisation;
- if (lw.lock_word & LOCK_WORD_FAT_HASH) {
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- sync = lw.sync;
- } else if (!(lw.lock_word & LOCK_WORD_THIN_HASH)) {
- sync = lw.sync;
- }
- if (sync && sync->data)
- return &sync->data;
- return NULL;
+ if (lock_word_is_inflated (lw)) {
+ MonoThreadsSync *mon = lock_word_get_inflated_lock (lw);
+ return (guint32)mon->data;
+ }
+ return 0;
}
/*
void
mono_monitor_enter_v4 (MonoObject *obj, char *lock_taken)
{
- if (*lock_taken == 1)
- mono_raise_exception (mono_get_exception_argument ("lockTaken", "lockTaken is already true"));
+
+ if (*lock_taken == 1) {
+ mono_set_pending_exception (mono_get_exception_argument ("lockTaken", "lockTaken is already true"));
+ return;
+ }
ves_icall_System_Threading_Monitor_Monitor_try_enter_with_atomic_var (obj, INFINITE, lock_taken);
}
gboolean
ves_icall_System_Threading_Monitor_Monitor_test_owner (MonoObject *obj)
{
- MonoThreadsSync *mon;
-
+ LockWord lw;
+
LOCK_DEBUG (g_message ("%s: Testing if %p is owned by thread %d", __func__, obj, mono_thread_info_get_small_id()));
- mon = obj->synchronisation;
-#ifdef HAVE_MOVING_COLLECTOR
- {
- LockWord lw;
- lw.sync = mon;
- if (lw.lock_word & LOCK_WORD_THIN_HASH)
- return FALSE;
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- mon = lw.sync;
- }
-#endif
- if (mon == NULL) {
- return FALSE;
- }
-
- if (mon_status_get_owner (mon->status) == mono_thread_info_get_small_id ()) {
- return(TRUE);
+ lw.sync = obj->synchronisation;
+
+ if (lock_word_is_flat (lw)) {
+ return lock_word_get_owner (lw) == mono_thread_info_get_small_id ();
+ } else if (lock_word_is_inflated (lw)) {
+ return mon_status_get_owner (lock_word_get_inflated_lock (lw)->status) == mono_thread_info_get_small_id ();
}
return(FALSE);
gboolean
ves_icall_System_Threading_Monitor_Monitor_test_synchronised (MonoObject *obj)
{
- MonoThreadsSync *mon;
+ LockWord lw;
LOCK_DEBUG (g_message("%s: (%d) Testing if %p is owned by any thread", __func__, mono_thread_info_get_small_id (), obj));
-
- mon = obj->synchronisation;
-#ifdef HAVE_MOVING_COLLECTOR
- {
- LockWord lw;
- lw.sync = mon;
- if (lw.lock_word & LOCK_WORD_THIN_HASH)
- return FALSE;
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- mon = lw.sync;
- }
-#endif
- if (mon == NULL) {
- return FALSE;
- }
-
- if (mon_status_get_owner (mon->status) != 0) {
- return TRUE;
+
+ lw.sync = obj->synchronisation;
+
+ if (lock_word_is_flat (lw)) {
+ return !lock_word_is_free (lw);
+ } else if (lock_word_is_inflated (lw)) {
+ return mon_status_get_owner (lock_word_get_inflated_lock (lw)->status) != 0;
}
-
+
return FALSE;
}
void
ves_icall_System_Threading_Monitor_Monitor_pulse (MonoObject *obj)
{
+ int id;
+ LockWord lw;
MonoThreadsSync *mon;
-
+
LOCK_DEBUG (g_message ("%s: (%d) Pulsing %p", __func__, mono_thread_info_get_small_id (), obj));
- mon = obj->synchronisation;
-#ifdef HAVE_MOVING_COLLECTOR
- {
- LockWord lw;
- lw.sync = mon;
- if (lw.lock_word & LOCK_WORD_THIN_HASH) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked"));
- return;
- }
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- mon = lw.sync;
- }
-#endif
- if (mon == NULL) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked"));
- return;
- }
- if (mon_status_get_owner (mon->status) != mono_thread_info_get_small_id ()) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked by this thread"));
+ id = mono_thread_info_get_small_id ();
+ lw.sync = obj->synchronisation;
+
+ mono_monitor_ensure_owned (lw, id);
+
+ if (!lock_word_is_inflated (lw)) {
+ /* No threads waiting. A wait would have inflated the lock */
return;
}
+ mon = lock_word_get_inflated_lock (lw);
+
LOCK_DEBUG (g_message ("%s: (%d) %d threads waiting", __func__, mono_thread_info_get_small_id (), g_slist_length (mon->wait_list)));
-
+
if (mon->wait_list != NULL) {
LOCK_DEBUG (g_message ("%s: (%d) signalling and dequeuing handle %p", __func__, mono_thread_info_get_small_id (), mon->wait_list->data));
void
ves_icall_System_Threading_Monitor_Monitor_pulse_all (MonoObject *obj)
{
+ int id;
+ LockWord lw;
MonoThreadsSync *mon;
LOCK_DEBUG (g_message("%s: (%d) Pulsing all %p", __func__, mono_thread_info_get_small_id (), obj));
- mon = obj->synchronisation;
-#ifdef HAVE_MOVING_COLLECTOR
- {
- LockWord lw;
- lw.sync = mon;
- if (lw.lock_word & LOCK_WORD_THIN_HASH) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked"));
- return;
- }
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- mon = lw.sync;
- }
-#endif
- if (mon == NULL) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked"));
- return;
- }
- if (mon_status_get_owner (mon->status) != mono_thread_info_get_small_id ()) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked by this thread"));
+ id = mono_thread_info_get_small_id ();
+ lw.sync = obj->synchronisation;
+
+ mono_monitor_ensure_owned (lw, id);
+
+ if (!lock_word_is_inflated (lw)) {
+ /* No threads waiting. A wait would have inflated the lock */
return;
}
+ mon = lock_word_get_inflated_lock (lw);
+
LOCK_DEBUG (g_message ("%s: (%d) %d threads waiting", __func__, mono_thread_info_get_small_id (), g_slist_length (mon->wait_list)));
while (mon->wait_list != NULL) {
gboolean
ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms)
{
+ LockWord lw;
MonoThreadsSync *mon;
HANDLE event;
guint32 nest;
gboolean success = FALSE;
gint32 regain;
MonoInternalThread *thread = mono_thread_internal_current ();
+ int id = mono_thread_info_get_small_id ();
LOCK_DEBUG (g_message ("%s: (%d) Trying to wait for %p with timeout %dms", __func__, mono_thread_info_get_small_id (), obj, ms));
-
- mon = obj->synchronisation;
-#ifdef HAVE_MOVING_COLLECTOR
- {
- LockWord lw;
- lw.sync = mon;
- if (lw.lock_word & LOCK_WORD_THIN_HASH) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked"));
- return FALSE;
- }
- lw.lock_word &= ~LOCK_WORD_BITS_MASK;
- mon = lw.sync;
- }
-#endif
- if (mon == NULL) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked"));
- return FALSE;
- }
- if (mon_status_get_owner (mon->status) != mono_thread_info_get_small_id ()) {
- mono_set_pending_exception (mono_get_exception_synchronization_lock ("Not locked by this thread"));
- return FALSE;
+
+ lw.sync = obj->synchronisation;
+
+ mono_monitor_ensure_owned (lw, id);
+
+ if (!lock_word_is_inflated (lw)) {
+ mono_monitor_inflate_owned (obj, id);
+ lw.sync = obj->synchronisation;
}
+ mon = lock_word_get_inflated_lock (lw);
+
/* Do this WaitSleepJoin check before creating the event handle */
mono_thread_current_check_pending_interrupt ();
/* Save the nest count, and release the lock */
nest = mon->nest;
mon->nest = 1;
- mono_monitor_exit (obj);
+ mono_memory_write_barrier ();
+ mono_monitor_exit_inflated (obj);
LOCK_DEBUG (g_message ("%s: (%d) Unlocked %p lock %p", __func__, mono_thread_info_get_small_id (), obj, mon));
* is private to this thread. Therefore even if the event was
* signalled before we wait, we still succeed.
*/
+ MONO_PREPARE_BLOCKING;
ret = WaitForSingleObjectEx (event, ms, TRUE);
+ MONO_FINISH_BLOCKING;
/* Reset the thread state fairly early, so we don't have to worry
* about the monitor error checking
/* Regain the lock with the previous nest count */
do {
- regain = mono_monitor_try_enter_internal (obj, INFINITE, TRUE);
+ regain = mono_monitor_try_enter_inflated (obj, INFINITE, TRUE, id);
if (regain == -1)
mono_thread_interruption_checkpoint ();
} while (regain == -1);
/* Poll the event again, just in case it was signalled
* while we were trying to regain the monitor lock
*/
+ MONO_PREPARE_BLOCKING;
ret = WaitForSingleObjectEx (event, 0, FALSE);
+ MONO_FINISH_BLOCKING;
}
/* Pulse will have popped our event from the queue if it signalled
projects / mono.git / blobdiff